1. Field of the Invention
This invention relates to a method and system for the placement and installation of a synthetic resin composite as an aesthetic restoration of the surface on a tooth, which is otherwise discolored or disfigured.
2. General Background of the Invention
The placement of composites or plastic surfacing or fillings, are widely used as aesthetic restorations. The restorations mimic the natural tooth color and shape to present a “filling”-which replaces or resurfaces the defective area of a tooth and thus creates a more pleasing appearance for the wearer. In the application of aesthetic fillings or restorations, it is usual that as soon as the composite material used placed and shaped, it is cured, or polymerized, customarily by light activation, using a special lamp and light guide to direct the high intensity light to the desired locations on the tooth. In the alternative, the composite may be cured by the inclusion of an added agent to promote polymerization, with the set-up of the material occurring without any additional assist. Those skilled in the art recognize that the application of composite and curing process is one which requires particular skill and technique to produce a composite on the tooth which has the requisite strength for long term use.
Common materials utilized in these composites are an acrylic resin which functions as a matrix for other contained materials. The composite may contain filler particles for strength, and color particles for color matching, or opaquers for concealing tooth discoloration. These filler particles are frequently accompanied by a coupling phase which facilitates the bonding of the various components. The resin most commonly used in aesthetic restorations is a bis-GMA, which is the reaction product of bisphenol A and a glycidal methacrylate. The resin is a dimethacrylate monomer which is induced to polymerize by the presence of free radicals (introduced by chemical reaction or by external energy such as heat or light). The chemically activated resins come usually as a two component system—a first paste containing a benzol peroxide initiator and the second containing a tertiary amine activator. Immediately prior to application, the two pastes are mixed, i.e., spatulated by hand with such as a spatula or blended by a mixing syringe, such that the amine reacts with the benzoyl peroxide to from free radicals that initiate the polymerization. This spatulated or blended mixture must be promptly applied to the tooth as the polymerization begins immediately, thereby leaving limited time for the dentist to form the restoration.
The light activated resin comes as a single paste, either in a syringe or a compule. The paste contains the photoinitiator module (usually camphroquinone) and an amine activator. When the resin is exposed to a special light, the photoinitiator becomes excited and reacts with the amine to produce the free radicals, which initiate the polymerization process. It should be appreciated that the composite begins to polymerize upon exposure even to normal room light and that the special light the process is accelerated and carried out to a greater depth in the composite.
Whether the resin is applied to the tooth by spatula, syringe or compule, the placement is critical, as is the application of a properly limited amount, neither too much nor too little, so that the formation of the restoration may be affected quickly. Certain embodiments of the present invention, as will become evident, greatly facilitate the placement of the proper amount of resin and its expedited shaping for an effective, expedient restoration.
The present invention is directed to a novel carrier for the application of the composite and a novel packaging of a carrier supported compule of restorative resin for the expedient aesthetic restoration. In the pre-packaged composite, preferably the resin is the light activated variety which cures primarily when exposed to a curing light. Use of this particular resin provides a much longer (comparatively) “working” time, in that it sets up principally under the curing light, and when exposed, it does so more rapidly than the chemically activated resins. It must be appreciated however, that the light activated resins only cure to the depth of the light penetration, so deep restorations may require the application of multiple layers of resin. While more difficult to mix, a two component system could be packaged on a carrier for the described application and shaping.
While the choice and application of the particular resin in the aesthetic restoration is of paramount importance, these factors are only part of those considered in the process. Integral steps of the restoration include the draping or damming of the site of the procedure. It is customary in the preparation of a tooth for an amalgam or aesthetic restoration that the tooth be isolated from those around it throughout the procedure. In the instance of application of an aesthetic restoration, care is taken to ensure that the added resin is precluded from contacting adjacent teeth, and keeping the interstices open between teeth. Accordingly, the present invention provides for a carrier for the resin which facilitates the draping and subsequent shaping of the resin as well as the packaging and management of a single dose of such as a light activated resin composite, enabling the convenient and efficacious placement of the resin on the selected tooth for working into an aesthetic restoration.
Patents have issued on different dosage and packaging features, from general purpose to special purpose for dental products. By way of example, a patent to Volker Marckardt (U.S. Pat. No. 3,756,386) discloses a multi-chamber container for separately carrying reacting materials which, when mixed, are ready for use as dental composites.
U.S. Pat. No. 4,921,137 discloses a dispensing container for liquid or paste type materials. U.S. Pat. No. 5,947,278 to Sawhney discloses a single-dose, double cup package for dental materials.
U.S. Pat. No. 4,125,190 to Davie, et al, discloses blister packaging which is child resistant.
A patent to Werner Schmidt, et al (U.S. Pat. No. 5,472,991) is directed to a photopolymerizable dental compound for curing in two curing steps.
U.S. Pat. No. 5,636,736 to Jacobs, et al discloses packaging for curable materials, namely orthodontic brackets which are attached to teeth and subsequently connected to retainers and the like for straightening or repositioning teeth. U.S. Pat. Nos. 4,978,007 and 5,762,192 also disclose additional packaging for curable materials.
U.S. Pat. No. 6,159,009 to Berk, et al, is discloses an amalgam carrier or syringe for a packaged composite resin for dental restorations. The carrier and replacement sleeves are specifically for carrying light activated resins.
U.S. Pat. No. 6,261,094 to Dragan discloses a syringe for a unit dose of composite materials to a tooth, specifically overcoming stated prior art problems of spatula, palate or like tool. The patent contains a recitation of several patents to capsule syringe dispensers for placement of composite materials.